<?php

// $num  = 100;

// $orderId  = 200;


$a = 100;
$b = &$a;
$a = 200;

var_dump($a);
var_dump($b);


$a = "xbs8";


$$a  = 90;

var_dump($xbs8);



$num1 = 100;

$num2 = 200;

$c = $num1;

$num1 = $num2;

$num2 = $c;

$age

$name

$sex